Structural member

ABSTRACT

A structural member for residential, commercial and other types of buildings, to serve the function of such components as joists, studs and beams, is comprised of a body of high impact plastic with an internal or external strip of sheet metal. The attachment to these structural members of other structural components, such as flooring, ceiling panels or wall panels, is accomplished by pointed fastening devices such as nails penetrating the sheet metal associated with the plastic members. The combination of the metal and the plastic in surface contact with each other will reliably retain these fastenings whereas the plastic alone or the sheet metal alone might be incapable of retaining them.

Unlted States Patent 1 91 1111 3,922,828 Patton 1 1 Dec. 2, 1975 1 1STRUCTURAL MEMBER 3,484,331 12/1969 Betz 52/309 x 1751 Inventor DavidPamm, Orange ijiiiiiii i/lZZZ liitraij... 23/383 73 AssigneezTridnternational Corporation 3,813,834 6/1974 Davis, Jr. 52/364 XOrange, Calif.

Primary Examiner--Ernest R. Purser [22] 1973 Assistant Examiner-WilliamRandolph [21] Appl. No.: 416,046 Attorney, Agent, or Firml(nobbe,Martens, Olson,

Hubbard & Bear [52] US. Cl. 52/368; 52/309; 52/720;

52/727 57 ABSTRACT [51] Int. Cl. E04C 3/29 5 Field f Search 52/309, 364,367, 368, A structural member for residential, commercial and 1 52/376725 other types of buildings, to serve the function of such componentsasjoists, studs and beams, is comprised of 5 References Cited a body ofhigh impact plastic with an internal or exter- UNITED STATES PATENTS nalstrip of sheet metal. The attachment to these structural members ofother structural components, such as flooring, ceiling panels or wallpanels. is accomplished 2:111:110 3/1938 oenismismsii :1: 52/760 bypointed fastening i Such as nails. Penetrating 2,134,674 10/1938shermanm 52/376 the sheet metal assoc1ated with the plastlc members.3017672 H1962 52/241 The combination of the metal and the plastic insur- 3 03 5/1963 Hanock 5 x face contact with each other will reliablyretain these 3,160,280 12/1964 Burch 1. 52/241 fastenings whereas theplastic alone or the sheet metal 3,179,983 4/1965 Webber 52/376 alonemight be incapable of retaining them. 3,381,432 5/1968 Brandwein 52/3093,401,494 9/1968 Anderson 52/309 2 Claims, 4 Drawing Figures US. PatentDec. 2, 1975 STRUCTURAL MEMBER BACKGROUND OF THE INVENTION It has longbeen the custom to construct the skeletal portions of small buildings,such as residences, farm buildings, small commercial buildings such asstores, from wooden components. Those skeletal portions of the structureare the floor supports, ceiling supports, roof supports and wallframing, and the elements that make up these skeletal portions of thestructures are usually called joists in the case of floor and ceilingstructures, rafters in the case of roofsupports, and studs making up thewall framing. A thickness of two inches is familiar in all of thesetypes of building structure components, and widths of four inches, sixinches, eight inches and ten inches are equally familiar, four inchesbeing the usual widths of studs and the other widths being found injoists and rafters.

It has been the custom to use wood in the making of these buildingcomponents. This involved the processing of the wood from forest tofinished product including, as a very important step, drying andseasoning of the wood to minimize warping after the wooden element hasbeen incorporated into the framing of a building. Timber being a productof nature, the worlds supply is not inexhaustable, and utilization isconstantly increasing as the worlds population increases. Conservationprograms, including reforestation, have been launched to replenish thesupply of timber but these programs are slow in coming to fruition.Moreover there are significant areas of the world in which timber forsupplying these structural components is not available.

SUMMARY OF THE INVENTION It follows from the foregoing that aconveniently usable and inexpensive substitute for wooden studs andother building components is needed, and the present invention embodiessuch a substitute. In the preferred embodiment of the invention theprincipal component of the stud or beam is a molded body having thedimensions of the wooden structure member for which it is a substitute,formed of an expanded synthetic polymer composition. For example it maybe a high impact polyester foam such as polyurethane, polystyrene,polyethylene or polypropylene. It may be a phenolic resin, an epoxy foamor a foamed silicone. The body of plastic material has associated withit a strip, preferably coextensive with the body of plastic in itslongitudinal dimension, of sheet metal. The sheet metal strip may be asurface covering or it may be molded into the interior of the plasticbody. In accordance with one embodiment of the invention the metal stripis in channel form adhesively attached to the exterior of the body ofplastic material and in accordance with another embodf ment of theinvention it is Z-shaped and is entirely encased in the plastic body.The metal of which the strip is formed is of a thickness and texture toaccommodate penetration by pointed'fastening devices, such as riails, inimperforate areas, but of sufficient thicknessiand stiffness to retainits shape apart from and prior to incorporation into the product. Thesheet metal performs an important function in the retention of fastenerssuch as nails and in addition it contributes a reinforcing effect to thefinished product. If the sheet metal is perforated in areas wherenailsare to be driven, the perfora- DESCRIPTION OF THE DRAWINGS For acomplete understanding of the invention reference may be had to thefollowing detailed description, to be interpreted in the light of theaccompanying drawings wherein:

FIG. 1 is a perspective view of an end fragment portion of an embodimentof the invention,inthe configuration of a two-by-four with the sheetmetal strip carried on the exterior;

FIG. 2 is a cross-sectional view of a structural member as in FIG. 1with a fragment of another structural member, which might be a wallpanel or a plank, secured thereto by means ofa nail;

FIG. 3 is a cross-sectional view similar to FIG. 2 but showing anembodiment of the invention in which the sheet metal strip is entirelyencased in the plastic material and is Z-shaped; and

FIG. 4 is an end view showing an extension of the concept shown in FIG.1, to serve the purpose of a rail, such as for aligning and supportingstuds.

DETAILED DESCRIPTION Referring now to the drawings and particularly toFIG. I the reference numeral 10 designates a body of plastic material,preferably an expanded synthetic polymer composition. As set forthhereinbefore it may be polyurethane, polystyrene, polyethylene orpolypropylene. It may be a phenolic resin, an epoxy foam or a foamedsilicone. It will be generally identified hereinafter as comprised of ahigh impact polyester foam. As indicated in FIG. 1 the body of polyesterfoam is surrounded on three sides by, and accordingly fills, a channeldesignated generally by the reference numeral 12, preferably of sheetmetal and comprised of a web portion 14 and side flanges or walls 16.The side walls or flanges 16 are, in the embodiment shown in FIG. 1,normal to the web portion 14 and are of equal height. With the exposedsurface of the body of polyester foam flat and flush with the free edgesof the side walls 16 of the channel 12 the combination of the body ofpolyester foam and the sheet metal channel has a rectangularcross-section. The particular embodiment shown in FIG. 1 has thecross-sectional proportions of a two-byfour, but it will be understoodthat it could have the cross-sectional proportions of any of the woodencomponents used in construction projects, such as, for example,one-by-one, two-by-two, two-by-six, two-byeight, two-by-ten,four-by-four, or the proportions of planking. It may correspond inlength to any of the usual wooden structural framing components.

The structural component shown in FIG. 1 may be made by confining thechannel 12 on its three sides to prevent deformity of the channel due toexpansion of the foamed plastic, by covering the top of the channel 12to confine the plastic material to the dimensions of the channel 12, andby injecting the polyester foam producing ingredients intothe coveredcha nel. By confining the sheet metal channel to the desiredconfiguration on three sides and confining the polyester foam within thechannel, expansion of the foam in any direction is prevented and thedesired density of the? polyester foam may be achieved.

Densities of the expanded polymer composition, when cured, may beachieved in a range from one pound per cubic foot to densities in therange of forty to fifty pounds per cubic foot. By comparison, white pinegenerally ranges from twenty-two to about thirtyone pounds per cubicfoot and yellow pine from twenty-three to thirty-seven per cubic foot.It has been found that structural components such as exemplified in FIG.1 which are somewhat lighter than conventionally employed woodenequivalents have as great or greater load bearing capability than thewooden equivalents. They are also chemically and physically stable, arenot subject to decay, and are fire resistant to the point of beingself-extinguishing.

The sheet metal of which the channel 12 is formed is preferably aferrous metal of sufficient thickness to be self-supporting as a channelprior to the filling of the channel with the polyester foam. A thicknessin a range from 26 to 30 gauge has been found to be adequate for thepurpose and its texture should be such that it is readily penetrable bypointed fastening devices such as nails, without prior perforation. Thepolyester foam bonds firmly to the surface of the metal without anyspecial treatment of the metal surface, although the bonding may beenhanced by a previous coating of the metal with any commonly availablepaint. The polyester foam-filled channel may be cut to desired lengthsby means of hand tools ordinarily employed on construction jobs.

It is the usual custom to secure to framing components such as studs,joists and rafters, other structural components such as flooring planksor panels, in the case of floor joists, wall board panels in the case ofstuds, and ceiling panels in the case of ceiling joists, by means ofnails. FIG. 2 shows a structural component, such as a wall board 20secured to a stud by means of a nail 22. A type of nail which has beenfound to be well adaped for securing structural components to studs orother structural members is called a ring-shank nail and it is this typeof nail that has been shown in FIG. 2. Another type of nail which hasalso been found well adapted for use for this purpose is the serratednail, a type of nail which has spiral ribs. If the sheet metal has athickness of 26 to 30 gauge as previously mentioned, the pointed nail 22may be driven through the imperforate metal.

The nail, in penetrating the metal, deforms the metal inwardly into asomewhat conically shaped ring or ridge as indicated at 24. Thedisplaced metal in turn penetrates the plastic and it appears that thepenetrated plastic exerts a pressure on the ring tending to force itinto contact with the shank of the nail. Depending upon the density ofthe plastic the displacemment of plastic by the shank of the nail afterit has passed beyond the ring 24 appears to generate a pressure of theplastic upon the shank of the nail and upon the rings of that shank sothat in a dense plastic the nail has fairly good gripping properties andreasonable resistence to withdrawal. However, with the metal penetratedby the nail and the ring 24 in engagement with the shank of the nail andbacked by the plastic, the combination of the sheet metal and theplastic has excellent nail retaining properties. It has been found thatthe force required to withdraw the nail from the metal clad structuralmember is comparable with or exceeds the force required to withdraw anail of equivalent size from an equivalent wooden structural member.

It will be recognized that apart from or in addition to any contributionby the displaced plastic to retention of the nail, either by directcontact of the plastic with the shank of the nail or by the exertion ofpressure by the plastic on the outside of the deformity in the metal,the composition of the metal may be such that it has memory propertiesbiasing the deformity in the metal into clinging engagement with theshank of the nail.

With regard to use of imperforate sheet metal, as mentionedhereinbefore, it should be understood that the use of perforated metalis not precluded, if for any reason an advantage might result from theuse of perforated metal. It would be desirable, in that event, that theperforations be small' relative to the diameter of nails likely to beused, so that regardless of where in relation to the perforations thepoints of nails might penetrate the metal, substantial deformity of themetal will occur.

FIG. 3 shows an alternative form of structural element in accordancewith the invention, and this has also been shown in the configuration ofa two-by-four. In this embodiment of the invention, the sheet metalmember 30 is Z-shaped and is entirely encased in the plastic 32. TheZ-shaped strip of metal 30 which is encased in the plastic member 30throughout the length of that member serves to reinforce the member andthis reinforcement is enhanced if the bends in the metal are quitesharp.

With the form of the structural member in FIG. 3, panels or otherstructural components may be secured thereto on any of the four sides,because a nail driven from any side, if of sufficent length, willpenetrate and be gripped by the metal contained in the structuralmember. FIG. 3 shows in fragmentary form panels or other structuralmembers attached to an edge as well as to a face of the plastictwo-by-four.

Still another embodiment of a structural member in accordance with thepresent invention is shown in FIG. 4. It represents a track which may beemployed, in the position shown, as a floor track for supporting andaligning a row of studs in the construction of a wall. In an invertedposition, it may be employed as a ceiling track to fit over and alignthe studs forming a wall.

The track member, designated generally by the reference numeral 40resembles the structural member in FIG. 1 in that it is comprised of abody of plastic material 42 encased on three sides by a sheet metalchannel comprised of a web portion 44 and side flanges 46. The sideflanges extend higher than the exposed surface of the body of moldedplastic 42 and these extensions 48 preferably bend inwardly slightly atthe point where they clear the upper surface of the plastic.

The exposed surface of the molded plastic member 42 serves as thesupport for the lower ends of studs, one of which is shown in FIG. 4 anddesignated by the reference numeral 49, and the studs may be fitted intoposition by rotating them about their own centers sufficiently to lowerthem between the extensions 48 of the flanges 46 and then twisting themso that from edge to edge they stand transversely of the molded plasticmember 42, the extensions 48 of the flanges 46 being spread apart as thetwisting takes place. The track member 40 may be nailed to thesupporting floor or surface by nails driven downwardly through theexposed surface of the plastic member 42 before or after the studs aremounted, or nails may be driven into the member 44 obliquely downwardlythrough either or both of the flanges 46 and through the web portion 44and into the supporting surface. Also, studs mounted in position on thetrack 40 may be secured thereto by nails driven obliquely downwardlythrough either face of the stud and through its lower end and into theexposed surface of the track 40, or obliquely downwardly through eitheror both of the extensions 48 of the flanges 46 into the edge of the studand downwardly through its end and into the plastic portion of the track40. Alternatively, it may be found adequate merely to drive nailsstraight into the studs from the sides through the extensions 48 of theflanges 46, through the flanges 16 of the stud l2 and into the stud.

What is claimed is:

l. A structural element for incorporation into structures such asprivate and public buildings and for retaining wall components and thelike which comprises:

an elongate molded body having at least two generally flat surfacesdisposed in parallel planes and formed of an expanded synthetic polymercomposition; and

a sheet metal member encased in the molded body generally coextensivewith the molded body longitudinally thereof and said sheet metal bodyhaving a Z-shaped cross-sectional configuration and being formed of ametal having sufficient stiffness to provide self maintenance of theZ-shaped cross-section yet having a penetrability to accommodate thedriving of nails therethrough and so disposed in said molded body as tohave the portions representing the arms of the Z-shape occupying planesgenerally parallel to and spaced inwardly from the aforementioned flatfaces of the molded body and the intermediate portion of the Z-shapeextending obliquely of the arms between opposite ends of the said armsof the Z-shape to accommodate penetration of the embedded sheet metalmember by nails of appropriate length driven into the molded body fromeither of the aforementioned flat faces and also nails driven into themolded body between and generally parallel to arms of said Z-shape withresultant deformity of the sheet metal into the portion of the moldedbody that is backing the sheet metal on the side opposite the side ofpenetrative entry of the nail.

2. A structural element as defined in claim 1 wherein:

the molded body has a rectangular cross-section other than square; and

the orientation of the Z-shaped metal member disposes the arm portionsthereof generally parallel to the planes of the narrow faces of themolded body.

1. A structural element for incorporation into structures such asprivate and public buildings and for retaining wall components and thelIke which comprises: an elongate molded body having at least twogenerally flat surfaces disposed in parallel planes and formed of anexpanded synthetic polymer composition; and a sheet metal member encasedin the molded body generally coextensive with the molded bodylongitudinally thereof and said sheet metal body having a Z-shapedcross-sectional configuration and being formed of a metal havingsufficient stiffness to provide self maintenance of the Z-shapedcrosssection yet having a penetrability to accommodate the driving ofnails therethrough and so disposed in said molded body as to have theportions representing the arms of the Z-shape occupying planes generallyparallel to and spaced inwardly from the aforementioned flat faces ofthe molded body and the intermediate portion of the Z-shape extendingobliquely of the arms between opposite ends of the said arms of theZ-shape to accommodate penetration of the embedded sheet metal member bynails of appropriate length driven into the molded body from either ofthe aforementioned flat faces and also nails driven into the molded bodybetween and generally parallel to arms of said Z-shape with resultantdeformity of the sheet metal into the portion of the molded body that isbacking the sheet metal on the side opposite the side of penetrativeentry of the nail.
 2. A structural element as defined in claim 1wherein: the molded body has a rectangular cross-section other thansquare; and the orientation of the Z-shaped metal member disposes thearm portions thereof generally parallel to the planes of the narrowfaces of the molded body.